Well, it depends (tm). If you're talking about *indexed* terms, then the value is stored only once in both the cases you mentioned below. There's really very little difference between a non-multi-valued field and a multi-valued field in terms of how it's stored in the searchable portion of the index, except for some position information.
So, having an XML doc with a single-valued field <field name="category">computers laptops</field> is almost identical (except for position info as positionIncrementGap) as a <field name="category">computers</field> <field name="category">laptops</field> multiValued refers to the *input*, not whether more than one word is allowed in that field. Now, about *stored* fields. If you store the data, verbatim copies are kept in the storage-specific files in each segment, and the values will be on disk for each document. But you probably don't care much because this data is only referenced when you assemble a document for return to the client, it's irrelevant for searching. Best Erick On Tue, Aug 9, 2011 at 8:02 PM, Kevin Osborn <osbo...@yahoo.com> wrote: > Please verify my understanding. I have a field called "category" and it has a > value "computers". If I use this same field and value for all of my > documents, it is really only stored on disk once because "category:computers" > is a unique term. Is this correct? > > But, what about multi-valued fields. So, I have a field called "category". > For 100 documents, it has the values "computers" and "laptops". For 100 other > documents, it has the values "computers" and "tablets". Is this stored as > "category:computers", "category:laptops", "category:tablets", meaning 3 > unique terms. Or is it stored as "category:computers,laptops" and > "category:computers,tablets". I believe it is the first case (hopefully), but > I am not sure. > > Thanks.
